Arid Zone Research ›› 2021, Vol. 38 ›› Issue (4): 1065-1074.doi: 10.13866/j.azr.2021.04.18

• Weather and Climate • Previous Articles     Next Articles

Phenology of forest vegetation and its response to climate change in the Qinling Mountains

YANG Qi1,2(),LI Shuheng1,2(),LI Jiahao1,2,WANG Jiachuan1,2   

  1. 1. College of Urban and Environment Science, Northwest University, Xi’an 710127, Shaanxi, China
    2. Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity, Xi’an 710127, Shaanxi, China
  • Received:2021-03-15 Revised:2021-05-09 Online:2021-07-15 Published:2021-08-03
  • Contact: Shuheng LI E-mail:yangqi547@163.com;lish@nwu.edu.cn

Abstract:

It is important to investigate the vegetation phenology pattern and the driving mechanism of vegetation phenology change in a mountain transition zone. In this study, we used the double logistic curve fitting method to extract the phenological parameters of forest vegetation in the Qinling Mountains on the basis of the moderate resolution imaging spectro radiometer and normalized difference vegetation index time-series images from 2000 to 2018. Combining temperature and precipitation data, we performed trend analysis, correlation analysis, and redundancy analysis to study the characteristics of time and space changes in different phenological periods and the response to climate elements in the Qinling area. The following results were obtained: (1) The start and end of the growing season ranged from 60 days to 102 days and from 315 days to 345 days, respectively. The length of the growth season ranged from 225 days to 255 days. From a spatial perspective, it has evident vertical zone distribution characteristics. With an increase in altitude, the start, end, and growth periods of phenology were delayed, advanced, and shortened, respectively. (2) The beginning of phenology was advanced, whereas the end of phenology was postponed. The proportions of pixels in advance and delayed phenologies were 62.25% and 53.42%, respectively. The length of the growing season exhibited a lengthened trend of 59.18%. Of the significantly extended area, 5.12% area was mainly located in the middle and high altitude areas of the central and eastern regions. (3) The initial period of vegetation phenology was negatively correlated with the average temperature and precipitation from February to May, accounting for 50.29% and 65.24% of the total area, respectively. The end of phenology was positively correlated with the average temperature and precipitation from August to November, accounting for 66.63% and 59.77% of the total area, respectively. (4) Redundancy analysis results show that the vegetation phenology in the Qinling Mountains was affected by both the current season and the earlier period of meteorological factors. The spring phenology was more affected in the phenology occurrence period than in the winter of previous year. Compared with autumn weather factors, temperature and precipitation in the early period of phenology exhibit a more significant relationship with the end of phenology. The phenological changes of different slopes exhibit different responses to meteorological factors.

Key words: phenological change, meteorological factors, redundancy analys, Qinling